This invention relates to the construction of outdoor household doors and, more specifically, weather-tight seals for the sill of outdoor household doors used in regions where the climate is relatively harsh in winter.
In the face of the increasing heating costs, it is becoming more and more important to reduce as much as possible the infiltration of air through doors and windows. It appears that one of the major sources of air infiltration is through the bottom of the principal doors of dwellings. It is therefore not surprising to note that there exist many ways of constructing outdoor door sills. The following American patents illustrate many models of door bottoms: Haskell, U.S. Pat. No. 926,409, June 29, 1909; Anderson, U.S. Pat. No. 1,768,730; Hehr et al, U.S. Pat. No. 2,795,015, June 11, 1957; Ghormley, U.S. Pat. No. 2,976,584, Mar. 28, 1961; and Coller, U.S. Pat. No. 4,055,917, Nov. 1, 1977. Despite this, the infiltration of air through the bottom of doors subsits because the door sill and the frame of all exterior doors have a tendency to shift once construction is finished.